Agitation during fermentation

[Jay]

Curious on thoughts of those agitating their fermentations. We currently ferment open top 300 gallon batches. I have spoken to some distillers who see an extra ABV point by continuously agitating throughout the fermentation cycle.

I'm not trying to start a debate our fermentation philosophy just curious at a high level if you have found it beneficial to continuously agitate your fermentations.

[SpiritedConsultant]

Agitation during fermentation is primarily useful if you have a highly flocculent yeast and/or a lot of solids. If you agitate in a manner that introduces additional O2, could actually reduce your yields, as the yeast will propagate at the expense of ethanol production.

[JohninWV]

I can't imagine there's any good reason to agitate a grain-in fermentation. Post fermentation, like a beer well for example, is pretty harmless and routine but you do need to watch O2.

[Jay]

The O2 introduction was my main concern but I tend to agree that agitation isn't necessary.

[Dehner Distillery]

I would say that we swear by agitating the ferment. A very slow agitation is all you need. We find it will finish out faster, and have a higher yield. Especially near the end of the fermentation process it helps keep the yeast suspended so you get all the goody out of your batch.

[Jay]

Dehner, Are you practicing closed top or open top fermentation?

[Squarrel Barrel]

If you are using closed and cooling jacketed fermenters, it may be worthwhile agitating a fermentation with lots of solids to keep the temperature more even throughout the fermenter, and speed the yeast activity.

[andyman30]

During a tour of Bruichladdich, they mentioned that the agitation/oxidation of wash was very beneficial. It removes ethyl carbamate (spelling), which is a precursor to cyanide. It also promoted the interaction of sulfur and copper in the still, possibly benefiting the sensory profile and providing less sulfur in the final product.